Apparatus for assembling piston ring end guides

ABSTRACT

Apparatus for assembling with split expansion rings, end guides which carry integral self retaining frictional elements engageable with the ring at opposite sides of the ring gap. In sequence, an end guide unit is fed into position across the ring gap and is then pushed into position within the ring across the gap, the frictional retaining elements being forced into position between the spaced wall flange segments defining the channel within the ring in which the end guide is received.

United States Patent Mulligan APPARATUS FOR ASSEMBLING PISTON RING ENDGUIDES [75] Inventor: Jack E. Mulligan, Ferguson, Mo.

{73] Assignee: Ramsey Corporation, St. Louis, Mo.

[22] Filed: Sept. 12, 1973 [21] Appl. No.: 396,500

[52} US. Cl 29/211 D [51] Int. Cl B23q 7/10 [58] Field of Search 29/211D, 222, 200 P, 211 R [56] References Cited UNITED STATES PATENTS3,681,837 8/1972 Franklin 29/211 D 5,3 T 51 3.7 46 5,2 X 46 F Fl, 8/ as; 17.,

. 79, j J9 I, i iv /90 1 1 June 17, 1975 Primary Examiner-Thomas H.Eager Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen,Steadman, Chiara & Simpson [57] ABSTRACT Apparatus for assembling withsplit expansion rings, end guides which carry integral self retainingfrictional elements engageable with the ring at opposite sides of thering gap. In sequence, an end guide unit is fed into position across thering gap and is then pushed into position within the ring across thegap, the frictional retaining elements being forced into positionbetween the spaced wall flange segments defining the channel within thering in which the end guide is received.

16 Claims, I4 Drawing Figures PATENTEDJUN 1 1 ms 3 8 89,342

SHEET 2 F ig. 14

1 APPARATUS FOR ASSEMBLING PISTON RING END GUIDES This invention relatesto apparatus for assembling piston ring end guides or latches with thepiston rings, and is more particularly concerned with apparatus which isespecially efficient in assembling self-retaining end guides with thepiston rings.

In a common type of split piston ring employed as an expander or spacerexpander ring, normally used as part of an oil control ring assembly,two flat rail rings are maintained in axially separated position andexpanded radially outwardly by the spacer-expander ring. Duringinstallation of these rings into a piston groove and insertion of thepiston into the cylinder, the end portions of the split rings must beheld against overlapping and in proper endwise abutment. For thispurpose end guides or latches are employed to assure that the ends ofthe split ring will properly abut.

Inasmuch as the sole function of the end guides or latches is tomaintain the end alignment of the rings, the end guides or latches mustbe low cost and every effort must be made to maintain the cost ofassembling the end guides or latches with the rings to the barestminimum. To this end, a new and improved end guide has been devisedwhich comprises a single piece molded plastic unit having an elongatedlance portion projecting from a self-retaining head to extend across thegap in a ring within a radially outwardly opening channel of which theunit is received. In addition to a retaining head at one end, the unitalso carries integrally therewith a separable retaining element spacedfrom the head and engageable with the ring at the opposite side of thegap therein from the head end retaining element. A further economy hasbeen to mold a plurality of the end guides in a generally seriateladderform arrangement for seriatim detachment from the ladder andassembly with respective piston rings.

It is to the provision of new and improved apparatus for efficientassembly of the end guide units with the piston rings that the presentinvention is directed.

An important object of the present invention is to provide a new andimproved appartus for installing selfretaining end guides or latch unitswith piston rings.

Another object of the invention is to provide a new and improvedapparatus which is especially suitable for feeding end guides from asupply into position for assembly with piston rings.

A further object of the invention is to provide new and improvedapparatus which efficiently directs end guides from a supply intoposition for assembly with piston rings and sequentially assembles theend guides with the piston rings.

Still another object of the invention is to provide a new and improvedapparatus for assembling end guides with piston rings and which willautomatically operate in a complete sequential cycle including feedingan end guide into position for assembly with a piston ring and theneffecting actual assembly of the end guides with the piston rings,rapidly and efficiently.

Other objects, features and advantages of the invention will be readilyapparent from the following description of certain preferred embodimentsthereof, taken in conjunction with the accompanying drawings althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts embodied in the disclosure, andin which:

FIG. 1 is a fragmentary elevational view, partially in section, of apiston and cylinder assembly demonstrating utility of a piston ring ofthe type with which the present invention is concerned.

FIG. 2 is a fragmentary enlarged cross-sectional view of an oil controlpiston ring assembly received in a groove in the piston of FIG. 1.

FIG. 3 is a plan view of an expander-spacer ring equipped with an endguide or latch of the type with which the present invention isconcerned.

FIG. 4 is a fragmentary elevational view taken substantially along theline IV-IV of FIG. 3.

FIG. 5 is a fragmentary longitudinal sectional elevational view takensubstantially along the line VV of FIG. 4.

FIG. 6 is an enlarged sectional detail view taken substantially alongthe line VI-VI of FIG. 5.

FIG. 7 is an enlarged fragmentary sectional detail view takensubstantially along the line VIIVII of FIG. 5.

FIG. 8 is a fragmentary elevational view of an end guide unit supplyladder provided as a unitary plastic molding.

FIG. 9 is a front elevational view of apparatus for assembling the endguides with piston rings.

FIG. 10 is a top plan view of the apparatus of FIG. 9, takensubstantially in the plane of line X-X in FIG. 9.

FIG. 11 is an enlarged fragmentary sectional view taken substantiallyalong the line XI-Xl of FIG. 9.

FIG. 12 is a fragmentary enlarged sectional detail view takensubstantially along the line XII-XII of FIG. 9.

FIG. 13 is an enlarged fragmentary sectional elevational view takensubstantially along the line XIII-XIII of FIG. 10.

FIG. 14 is a schematic illustration of an operating electropneumaticcircuit for cyclical operation of the apparatus.

By way of background, there is shown in FIG. 1 a representative piston15 and cylinder 17 of an internal combustion engine wherein the pistonhas a plurality of ring assemblies mounted in its perimeter adjacent toits head end, including compression rings 18 and 19 and an oil ringassembly 20.

Referring now to FIG. 2, the oil ring assembly 20 includes anexpander-spacer ring 21 and two rail rings 22 and 27, the assembly beingreceived in a complementary ring groove 28 in the piston 10.

As best illustrated in FIGS. 2,3 and 4, the expanderspacer ring 21 is ofgenerally U-shape cross section providing a radially outwardly openingchannel 29 defined by a top row 30 and a bottom row 31 ofcircumferentially spaced flange segments which project radially inspaced parallel relation and are connected together at their radiallyinner edges by vertically extending web sections 32 integral therewiththrough axially extending respective reverse bend formations 33 againstwhich the radially inner edges of the rail rings 22 and 27 seat and arethrust radially outwardly to engage the wall of the cylinder 17. Forthis purpose the ring 21 is compressed from a normal expanded conditionwherein the flange segments 22 and 27 and the connecting sections 32 actas springs to generate a circumferential expanding force against therail rings 22 and 27.

In order for the expander-spacer ring 21 to function satisfactorily,split ends 34 at a gap 35 must not overlap but must abut insubstantially perfect alignment in the compressed condition of the ringwherein the gap 35 is closed. In order to avoid misalignment of the endsthere has been provided a new and improved form of gap latch or endguide 37 comprising a guide shaft 38 of a length to extend to asubstantial distance each side of the gap 35 when received within thechannel 29 and of a width only slightly smaller than the space betweenthe wall segments 30 and 31. Means for retaining the end guide 37 inplace in the assembly comprise retaining elements which are respectivelyfrictionally anchored to the ring at opposite sides of the gap 35 andprevent escape of the guide 37 after assembly with the ring.

In this instance one of the retaining elements comprises a head block39, integral at one end of the shaft 38, having lateral friction bosses40 on its sides to facilitate frictional retaining gripping engagementwith the confronting inner faces of the segments 30 and 31 at one sideof the gap 35 with the shaft 38 extending from the head 39 across thegap and to a substantial extent beyond the opposite end of the ringbetween the segments 30 and 31.

To retain the end guide 37 and more particularly the shaft portion 38against radially outward displacement from the channel 29 or endwiseescape during expansion of the ring 21 in fitting it over the piston 15,a second frictionally anchored retaining element 41 is provided whichengages in firm frictional relation with and between the segments 30 and31 adjacent the end 34 of the ring which is opposite to the end 34adjacent to which the head retaining element 39 is positioned. For thispurpose the element 41 is provided with respective side projectingfriction bosses 42 (FIGS. 4,5 and 7) which retain this element inoverlying relation to the shaft 38. A chamfered end edge 43 is directedtoward a barb-like shouldered tip 44 on the distal end of the shaft 38which faces generally toward the latch element 41.

In a preferred arrangement, the retaining element 41 is provided as anoriginally integral part of the end guide 37 so as to avoid the need forhandling separate parts, with the frictional resistance upon engagementof the bosses 42 with the segments 30 and 31 during assembly causing theelement 41 to detach from the shaft 38 so that after assembly the shaftcan move relative to the fixed latch element 41. For this purpose, theelement 41 is, as initially made, attached to the shaft 38 by afrangible neck 45 (FIG. 8). By molding the end guide 37 from suitableplastic material, the unitary structure of the shaft 38 and theretaining elements 39 and 41 can be readily effected according to anypreferred molding technique.

In order to facilitate supply and assembly operations, a plurality ofthe end connectors or guides 37 are preferably molded in a convenientspaced seriate, ladderlike arrangement 45 providing a suitable pluralityof the guides connected as by means of frangible connections 47 to acommon bar 48 at the head retaining elements 39, and by means offrangible connections 49 to a common bar 50 at the terminals of the tips44. Thereby the individual guides 37 can be readily broken from thespaced parallel bars 48 and 50 by rupturing the respective frangibleconnections 47 and 49, to supply the end guides seriatim to piston ringsas required. There may be as many of the guide units 37 in the supplyladder 46 as desirable or as may be conveniently handled in automatic orsemi-automatic assembly apparatus.

According to the present invention, new and improved apparatus forsemi-automatic assembling of the end guides or latches 37 with pistonrings 21 has been provided as exemplified in FIGS. 9-14. Moreparticularly, the apparatus is provided with means for receiv ing theend guides 37 in the ladder 46 supply arrangement, stripping the endguide units 37 successively from the supply ladder 46, feeding eachsuccessively stripped end guide 37 into position for assembly with arespective one of the piston rings 21, and completing the assembly bypress fitting the retaining element head 47 within the ring at one sideof the gap 35, and separating and press fitting the retaining element 41of the end guide into the ring at the opposite side of the gap over theshank 38 of the assembled end guide. For this purpose the apparatusincludes a magazine structure (FIGS. 9,10,11 and 13), which in thisinstance is equipped to handle the ladder-form supply of end guides, oneladder at a time, although it will be apparent that by suitableextension of the magazine structure a series of the ladders could beaccommodated. In this instance, vertical guide track means are providedfor receiving the ladder bars 48 and 50, comprising a vertical trackgroove 52 for the bar 48 and a vertical track groove 53 for the bar 50.The track grooves 52 and 53 guide the ladder 46 downwardly so that thelowermost of the end guides 37 rests upon a complementary feed surface54 extending in a front to rear direction and having a transversecurvature formed on a radius substantially complementary to the radiusof curvature of the outer diameter of the piston ring 21 and to whichcurvature the end connector shafts 38 are also desirably formed tofacilitate assembly of the end connectors with the rings. In the presentinstance, the feed surface 54 is provided on a member 55 providing ateach side of the feed surface at least in line with the track grooves 52and 53 escape clearances for discard of the bars 48 and as the endguides 37 are progressively stripped therefrom. Support for the memberis provided by body member in the form of a vertical plate 57 which alsosupports the magazine 51 and is mounted on a base provided by ahorizontal base plate 58 carried by a machine frame 59. Drop-out holes60 in the base plate 58 are provided in line with the track grooves 52and 53 for discard of the separated ladder posts 48 and 50 to a suitablescrap receptacle thereunder.

Each of the end guides 37 is successively stripped from the supplyladder and moved into position for assembly with one of the rings 21 bymeans of a reciprocable feed plunger 61 which is formed in complementaryshape to engage slidably with the feed surface 54 and is of a thicknessand a width to engage with substantially the entire length at the rearside of the end guide shaft 38 which lies upon the feed surface, as bestseen in FIGS. 11 and 13. Feeding stroke and return reciprocations of theplunger 61 are effected by means of a motor 62 desirably in the form ofa fluid operated, such as pneumatic, cylinder having a piston 63suitably attached as through the medium of a yoke bar 64 to the rear endof the plunger 61. Means such as mounting box 65 support the motor 62over the base plate 58. To assist in reciprocably guiding the plunger61, means comprising a fixed guide rod 67, projecting forwardly from thetop of the block 65 in spaced parallel relation to the piston rod 63,extends through a complementary guide aperture 68 in the yoke bar 64.

In a feeding stroke, the plunger 61 moves from a retracted position asshown in full line in FIG. 11, forwardly into engagement with the endguide 37 resting on the feed surface 54, stripping such end guide fromthe ladder bars 48 and 50 by breaking the respective connections 47 and49. Continued forward thrusting of the thus detached end guide 37 movesit through a clearance aperture 69 in the mounting plate 57 and finallyinto assembly position aligned with the channel 29 of one of the rings21 supported on a stepped mandrel 70 desirably comprising a forwardextension from the member 55 and offset concentrically relative to thefeed surface 54 equal to the radial dimension of the ring so that thefree edges of the flange segments 30 and 31 lie within the curved planeof the feed surface. Feed thrust of the plunger 61 is controlled todrive the end guide forwardly beyond the front end of the feed surface54 and into position directly over the channel 29 of the ring 21. Justas the end guide 38 reaches the assembly position over the ring 21, itis restrained against overshooting and is pressed down into the channel29 by means comprising a biasing leaf spring finger 71. In addition toits guide press-in function, the finger 71 desirably also serves as anaid to positioning the ring 21 and holding the ring in the properassembly position on the mandrel 70. For this purpose, the spring finger71 has an attachment terminal flange 72 received in a suitablecomplementary recess 73 in the back face of the mounting panel 57 andabove the clearance opening 69, means comprising the screws 74 securingthe flange in place and to position the spring finger in a downwardlyand forwardly oblique biasing position normally pressing downwardly andwith a slight rearward component of biasing pressure against the ringsegment flanges 31 whereby the ring is held down against the mandrel 70and against a rear locating shoulder 75 providing a drop-off from thefeed surface 54. For best results. the biasing spring finger 71 iscentered, as best seen in FIGS. 9, and 13, in the opening 69, and alongitudinal central clearance notch 77 is provided in the plunger 61 toclear the spring finger. To

facilitate moving the ring 21 into position under the spring finger 71,the front terminal end portion of the finger is turned up to provide acam lip 78. Thereby even though the normal spring bias of the finger 71causes it to be pressed below the radial width dimension of the ring 21,the ring can be pressed rearwardly into the assembly position under thefinger by camming the ring against the lip 78. Also the turned up curvedlip 78 facilitates smooth release of the ring 21 after assembly of theselected end guide 37 has been completed.

1n the present instance, mounting of the rings 21 on the mandrel 70 iseffected manually, although it will be readily apparent that suitablemechanical means may be provided for mounting the rings 21 successivelyin position for assembly of the ring guides therewith and then removalafter the assembly, automatically coordinated with other operations ofthe apparatus. To facilitate mounting of the rings in proper position tofacilitate assembly of the end guides therewith, the mandrel 70 is inthe form of a segment of a cylinder which is wide enough to support thering 21 equally at each side of the ring gap 35 within which is receiveda fixed locating key 79 (FIGS. 9, 10, 12 and 13) so located with respectto the feed opening 69 as to position the ring gap 35 in alignment withthe space between the retaining elements 39 and 41 of the end guides 37as they are fed to the ring with which to be assembled. Desirably thekey 79 is carried fixedly by the mandrel 70. Thereby, on mounting one ofthe rings 21 on the mandrel 70, its gap 35 must be properly located toreceive the key 79 therein between the ends 34 of the ring (FIG. 13).This properly locates the gap for reception of the retaining elements 39and 41 of the end guide within the respective end portions of the ring.

Means for driving the retaining elements 39 and 41 into their generallypress fit frictional retaining engagement within the end portions of thering 21 comprise an insertion plunger 80 (FIGS. 9, 12 and 13) which isguided reciprocably by a guide plate or bracket 81 mounted on theforward face of the supporting panel 57 in a position to engage anddrive the retaining elements 79 and 41 into the channel of the ring 21.Reciprocal cyclical driving and return strokes of the plunger 80 areeffected by suitable means comprising a motor 82 such as a fluidoperated, i.e. pneumatic, cylinder mounted on a suitable supportingbracket 83 (FIGS. 9 and 10) carried by the mounting plate 57. A pistonrod 84 of the motor 82 is suitably connected to the upper end of theplunger 80.

Means are provided for assuring proper alignment of the ring 21 on themandrel against the shoulder when the plunger is driven in an insertingstroke. To this end, the lower front end portion of the plunger 80carries fixedly therewith a downwardly extending alignment finger 85having a longitudinal downwardly opening notch 87 to clear the key 79and providing a pair of spaced finger projections 88 for alignmentengagement with each of the end portions of the ring 21 so that if thereis any misalignment due to warpage or any other reason of the endportions or if the ring has not been quite fully pushed toward theshoulder 75 during mounting of the ring, the alignment fingers 88 will,in advance of engagement with the end guide by the plunger 80 properlyalign the end portions of the ring. To facilitate this function, thefinger projections 88 extend beyond the driving end of the plunger 80and are provided with lead-end oblique cam surfaces 89 facing toward thering. To accommodate the finger projections 88, the mandrel 70 isprovided with respective clearance holes 90 at the respective oppositesides of the key 79.

In order to drive the retaining elements 39 and 41 into position withinthe ring 21 in proper sequence in the insertion stroke of the plunger80, its driving tip is properly profiled as best seen in FIG. 13, beingprovided with stepped driving shoulders 91 and 92 for the elements 39and 41, respectively, with the driving shoulder 91 projecting adesirable distance in advance of the shoulder 92. The steppeddifferential between the shoulders 91 and 92 is such that although theshoulder 92 engages the taper 43 of the element 41 and swings theelement 41 from its normal oblique projection from the shaft 38 towardthe shaft, the shoulder 91 will engage and start thrusting the retainingelement 39 into press fit engagement within the ring channel before theshoulder 92 so presses against the retaining element 41 as to possiblybreak it free from the shaft 38. Thereby, in the continuing insertionthrust of the plunger 80, the shoulder 91 first begins the press fitdrive of the element 39 into the ring channel followed by the shoulder92 pressing the element 41 into position in the channel at the oppositeside of the gap 35,

and in the final continuing thrust of the plunger 80 the element 41enters into press fit with the respective ring wall segments 30 and 31and being fully press fitted in place detaches from the shaft 38 whilethe shoulder 91 moves the element 39 into its fully driven positionwherein the shaft 38 underlies the element 41, substantially as depictedin FIG. 5. As soon as this operation has been completed, the plunger 80is backed off and the ring 21 loaded with the end guide 37 assembledtherewith is removed from the mandrel 70 and another ring placed inposition to have one of the end guides 37 assembled therewith in arepeat cycle. Such assembly cycles can be continued as long as there areend guides 37 in the ladder 46, the next succeeding of the end guides 37falling into position automatically as each preceding end guide isstripped from the ladder. It may be noted that the magazine tracks 52and 53 are of sufficient length so that when the operator observes thatthe upper end of the ladder has descended significantly below the top ofthe mounting plate 57, another ladder 46 can be inserted to continuedescending with the preceding ladder as one after the other of the endguides 37 is stripped therefrom in the operation of the machine.

Means are provided for coordinating operations of the plungers andeffecting the feeding and assembling functions in proper automaticsequence. In a semiautomatic operating sequence, the operator mounts oneof the rings 21 in position and then manually operates a device forinitiating a cycle of operation, such as pressing a starting button 93(FIG. 14) of an operating circuit functioning through means formaintaining the cycle of operation to completion comprising a relay 94which initially actuates an electrical device 95 to operate a valve 97to direct air from a source 98 to the feed slide motor 62, therebyenergizing it to feed one of the end guides 37 into position over thering to receive the same. As the feed plunger 61 reaches the end of itsfeeding stroke, a trip head 99 (FIG. carried by an arm 100 on the yoke64 strikes and moves a trip arm 101 ofa limit switch 102, therebysignaling the relay 94 to effect actuation of the electrical control 95to actuate the valve 97 to reverse the motor 62 and in sequence activatethe insertion plunger motor 82 in a driving stroke which is terminatedwhen a trip head 103 (FIG. 9) on a trip arm 104 carried by the plunger80 strikes and moves an actuating arm 105 of a limit switch 107 tosignal the relay for activating the electrical actuator 95 to reversethe plunger motor 82 and return the plunger 80 to its starting position,whereupon the cycle terminates until the starting button 93 is againpressed.

It will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

I claim as my invention:

1. Apparatus for assembling end guides with split piston rings ofchannel shape, comprising:

means for mounting a split piston ring in position to receive an endguide in assembly therewith and including means for properly locatingthe gap between ends of the ring at the ring gap;

means for positioning an end guide adjacent to the ring across the gapand aligned with the ring channel; and

inserting means for thrusting the end guide laterally into the ringchannel across the gap.

2. Apparatus according to claim I, wherein said means for supporting thering comprises a mandrel and said gap aligning means comprises a keycarried by the mandrel.

3. Apparatus according to claim 1, including means cooperative with saidinserting means for assuring alignment of the ends of the ring with oneanother and alignment of the end portions of the ring with saidinsertion means.

4. Apparatus according to claim 1, wherein said insertion meanscomprises a plunger having stepped thrusting shoulders for successivelydriving retaining elements of the end guide into engagement with therespective opposite end portions of the ring.

5. Apparatus according to claim 4, wherein said stepped shoulderscomprise a first shoulder for driving a terminal head element into pressfit within the ring channel up one side of the gap and a second shoulderfor driving a latch retaining element of the end guide into press fitengagement with the opposite end portion of the ring.

6. Apparatus according to claim 1, wherein said feeding means include afeed surface, and a feed plunger for driving the end guide from a supplyinto position with respect to the ring which will receive the end guide.

7. Apparatus according to claim 6, including a magazine for receiving aladder of seriate end guides, and said feeding means comprising a feedsurface on which the end guides of the ladder are successively received.and a plunger for stripping the end guides successively from the ladderand thrusting them along said feed surface into position for assemblywith the ring by said inserting means.

8. Apparatus according to claim 1, including means for cyclicallycoordinating operation of said feeding means and said inserting means.

9. Apparatus according to claim 8, wherein said feeding means includes afeeding plunger and a driving motor, said inserting means comprises aninserting plunger and a drive motor, and means for cyclically operatingsaid motors comprising a manually operable device for initiating thecycle and means for maintaining the cycle of operation to completionincluding sequential operation of said feeding means and said insertingmeans.

10. An apparatus for assembling elongated end guides with piston rings,comprising:

a feed surface;

a magazine for supplying end guides seriatim to said feed surface;

means for supporting a channeled piston ring with its channel alignedwith said surface to receive an end guide; and

a plunger for driving the end guide which is an engagement with saidsurface into position for insertion into the channel of the ring.

11. Apparatus according to claim 10, wherein said means for supporting aring comprises a stepped mandrel supporting the ring with its outerperimeter aligned with said surface, and means for holding the ring inposition relative to said surface to receive the end guide.

12. Apparatus according to claim 11, wherein said means for holding thering include a shoulder between said mandrel and said surface and abiasing element having components of biasing thrust toward said mandreland toward said shoulder.

13. Apparatus according to claim 12, wherein said biasing meanscomprises a spring finger functioning means for inserting the end guidesinto the ring channel includes a plunger. respective motors for drivingsaid plungers, and means for coordinating operation of said motors.

16. Apparatus according to claim 15, said means for coordinatingoperation of said motors including a circuit having respective limitswitches activated by means connected with said plungers.

1. Apparatus for assembling end guides with split piston rings ofchannel shape, comprising: means for mounting a split piston ring inposition to receive an end guide in assembly therewith and includingmeans for properly locating the gap between ends of the ring at the ringgap; means for positioning an end guide adjacent to the ring across thegap and aligned with the ring channel; and inserting means for thrustingthe end guide laterally into the ring channel across the gap. 2.Apparatus according to claim 1, wherein said means for supporting thering comprises a mandrel and said gap aligning means comprises a keycarried by the mandrel.
 3. Apparatus according to claim 1, includingmeans cooperative with said inserting means for assuring alignment ofthe ends of the ring with one another and alignment of the end portionsof the ring with said insertion means.
 4. Apparatus according to claim1, wherein said insertion means comprises a plunger having steppedthrusting shoulders for successively driving retaining elements of theend guide into engagement with the respective opposite end portions ofthe ring.
 5. Apparatus according to claim 4, wherein said steppedshoulders comprise a first shoulder for driving a terminal head elementinto press fit within the ring channel up one side of the gap and asecond shoulder for driving a latch retaining element of the end guideinto press fit engagement with the opposite end portion of the ring. 6.Apparatus according to claim 1, wherein said feeding means include afeed surface, and a feed plunger for driving the end guide from a supplyinto position with respect to the ring which will receive the end guide.7. Apparatus according to claim 6, including a magazine for receiving aladder of seriate end guides, and said feeding means comprising a feedsurface on which the end guides of the ladder are successively received,and a plunger for stripping the end guides successively from the ladderand thrusting them along said feed surface into position for assemblywith the ring by said inserting means.
 8. Apparatus according to claim1, including means for cyclically coordinating operation of said feedingmeans and said inserting means.
 9. Apparatus according to claim 8,wherein said feeding means includes a feeding plunger and a drivingmotor, said inserting means comprises an inserting plunger and a drivemotor, and means for cyclically operating said motors comprising amanually operable device for initiating the cycle and means formaintaining the cycle of operation to completion including sequentialoperation of said feeding means and said inserting means.
 10. Anapparatus for assembling elongated end guides with piston rings,comprising: a feed surface; a magazine for supplying end guides seriatimto said feed surface; means for supporting a channeled piston ring withits channel aligned with said surface to receive an end guide; and aplunger for driving the end guide which is an engagement with saidsurface into position for insertion into the channel of the ring. 11.Apparatus according to claim 10, wherein said means for supporting aring comprises a stepped mandrel supporting the ring with its outerperimeter aligned with said surface, and means for holding the ring inposition relative to said surface to receive the end guide. 12.Apparatus according to claim 11, wherein saId means for holding the ringinclude a shoulder between said mandrel and said surface and a biasingelement having components of biasing thrust toward said mandrel andtoward said shoulder.
 13. Apparatus according to claim 12, wherein saidbiasing means comprises a spring finger functioning also to press theend guide into the channel of the ring as delivered by said plunger. 14.Apparatus according to claim 10, wherein said magazine has spaced guidetracks for receiving side bars of a supply ladder of the end guides,wherein the end guides are attached at opposite ends to the bars inseriate relation, said plunger being operative to strip the end guidessuccessively from the ladder.
 15. Apparatus according to claim 10,wherein said means for inserting the end guides into the ring channelincludes a plunger, respective motors for driving said plungers, andmeans for coordinating operation of said motors.
 16. Apparatus accordingto claim 15, said means for coordinating operation of said motorsincluding a circuit having respective limit switches activated by meansconnected with said plungers.